Owen, sweetie
I guess most working ladies had the same experience in here...can you believe that I was harassed by my own boss in previous work?
I remember one of my customers who is a doc in University in Qatar, and he knew that I was married at that time. He simply decided to ignore the fact and kept on asking me out.
Imagine, that after long conversation where I have mentioned my marital status few times, he said "So can I call you sometime?"
The answer, with cool blood, was: "Sure, if you have any more questions about the product"

Some men do it straight in your face, some have a bit more decency...but it happens a lot anyway.

I am really more than willing to kick his butt for you...gosh, it would make me feel better for all the guys who are annoying us with this.

But, for real, if talking to your GM would not work, then I'd do few things:
Since he is from your place, I'd play on his pride a bit, saying that he should be ashamed of himself and he is creating a bad reputation for others from your place. And that kind of stuff...

If that wouldn't work, I'd say that if he wouldn't stop, I'd send him so quick back to his country, that he won't even know what happened! That you won't waste your time on going to the management anymore, you'll go straight to the police and let him know that from now on every conversation that you will have shall be recorded.
You can tell him that you switch the loudspeaker every time he calls or share the line with your boss.

If you need any help, I am here for you.

If you're looking for a problem, you're probably gonna find one.